[mkgmap-dev] a new DEM-File Option

Sun Oct 22 13:18:11 BST 2017

Hi,

Frank, thanks for your work. Your analysis of DEM headers looks good to 
me, I have done similar task for gmaptool. Yours is of course more 
detailed. I haven't looked at your program yet, but I hope it can create 
usable data.

Gerd, there are 2 flags in TDB. One is for DEM, other for using contours 
for calculating height profiles. See file tdbfmt/HeaderBlock.java, you 
already have both in code. I think the meaning of these flags in mkgmap 
is swapped, but I could be wrong.

When adding DEM to a tile, area of DEM can probably be bigger than tile, 
I have seen some examples, when people were using DEM from Garmin maps 
that way. DEM subfile can't have more layers than TRE but I think less 
layers should work.

When creating a map with DEM for PC, overview map should include DEM 
too. This could be a DEM with empty data, gmaptool can create that kind 
of DEM.

-- 
Best regards,
Andrzej